Demineralized corticocancellous bone sheet

Abstract

A flexible, demineralized unitary bone sheet comprised of cortical cancellous bone having a residual calcium weight of 3.0% to 8.0% with a hyaluronic acid component having a molecular weight of 700,000 to 1,500,000 with the weight of the same ranging from 1% to about 5% of the total sheet weight. The bone sheet is adapted for use during the in vivo repair of a mammalian or animal skeletal system with the thickness of the cortical cancellous sheet ranging from 2.0 mm to about 8.0 mm. The bone sheet has sufficient flexibility to allow the sheet to be shaped to conform to the configuration of a skeletal region to be repaired and sufficient tensile strength to allow the sheet to be so shaped without damage to the sheet.

1. A sterile flexible bone sheet for use during the in vivo replacement or reformation of preselected portions of an animal skeletal system comprising a continuous integral unitary sheet of demineralized natural bone with a cortical layer and a cancellous layer, said cortical layer interfacing with said cancellous layer through a cortical cancellous section, the thickness of said sheet ranging from 2.0 mm to 8.0 mm, the sheet being capable of being bent from its original shape to conform to the configuration of a skeletal region to be repaired without damage to the sheet, said sheet being capable of inducing osteogenesis at the skeletal region. 
     
     
       2. A sterile flexible bone sheet according to  claim 1  wherein the thickness of said sheet ranges from 2.0 mm to 6.0 mm. 
     
     
       3. A sterile flexible bone sheet according to  claim 1  wherein the thickness of said cortical layer ranges from 1 mm to 4 mm and the thickness of said cancerous layer ranges from 1 mm to 4 mm. 
     
     
       4. A sterile flexible bone sheet according to  claim 1  wherein said sheet has from 1% to 5% hyaluronic acid by weight. 
     
     
       5. A sterile flexible bone sheet according to  claim 1  wherein said cortical and said cancellous bone comprises from 99% to 95% by weight of the bone sheet. 
     
     
       6. A sterile flexible bone sheet according to  claim 1  wherein said demineralized sheet has residual calcium ranging from 3.0% to 8.0% by weight of the demineralized bone mass. 
     
     
       7. A sterile flexible bone sheet according to  claim 1  wherein said demineralized sheet has a neutral pH. 
     
     
       8. A sterile flexible bone sheet according to  claim 1  wherein said demineralized bone sheet has an osmolality ranging from 290 mmol/kg to 310 mmol/kg. 
     
     
       9. A sterile flexible bone sheet according to  claim 1  wherein said cortical cancellous bone sheet comprises from 99% to 95% by weight of the demineralized bone and from 1% to 5% by weight from a group consisting of hyaluronic acid, sodium hyaluronate and derivations thereof. 
     
     
       10. A sterile flexible bone sheet according to  claim 1  wherein said cortical cancellous bone sheet is cut from tibial allograft tissue. 
     
     
       11. A sterile flexible bone sheet according to  claim 1  wherein said cortical cancellous bone sheet is cut from femoral allograft tissue. 
     
     
       12. A sterile flexible bone sheet according to  claim 1  wherein said cortical cancellous bone sheet is cut from pelvic allograft tissue. 
     
     
       13. A sterile flexible bone sheet according to  claim 1  wherein said cortical cancellous bone sheet is cut from cancaneal allograft tissue. 
     
     
       14. A sterile flexible bone sheet for use during the in vivo replacement or reformation of preselected portions of a human bone comprising a continuous unitary sheet of demineralized natural bone including a cortical layer portion which interfaces with a cancellous layer portion with the thickness of said bone sheet ranging from 2.0 mm to 6.0 mm, said sheet having hyaluronic acid or derivatives thereof with a molecular weight over 700,000 Daltons added thereto at a concentration of 1.0 to 4.0 mg/ml, said sheet being flexible for application to a bone to be repaired without damage to the sheet, said sheet being capable of inducing osteogenesis at the bone region. 
     
     
       15. A sterile flexible bone sheet according to  claim 14  wherein the thickness of said cortical portion ranges from 1 mm to 3 mm and the thickness of said cancerous portion ranges from 1 mm to 3 mm. 
     
     
       16. A sterile flexible bone sheet according to  claim 14  wherein said demineralized sheet has residual calcium ranging from 3.0% to 8.0% by weight of the demineralized bone mass. 
     
     
       17. A sterile flexible bone sheet according to  claim 14  wherein said demineralized sheet has a neutral pH. 
     
     
       18. A sterile flexible bone sheet according to  claim 14  wherein said demineralized bone sheet has an osmolality ranging from 290 mmol/kg to 310 mmol/kg. 
     
     
       19. A sterile flexible bone sheet according to  claim 14  wherein said demineralized bone sheet comprises from 99% to 95% by weight of the demineralized cortical cancellous bone. 
     
     
       20. A sterile flexible bone sheet according to  claim 14  wherein said cortical layer interfaces with said cancellous layer through a cortical cancellous section. 
     
     
       21. A sterile flexible bone sheet according to  claim 14  wherein said cortical cancerous bone sheet is cut from tibial allograft tissue. 
     
     
       22. A sterile flexible bone sheet according to  claim 14  wherein said cortical cancerous bone sheet is cut from femoral allograft tissue. 
     
     
       23. A sterile flexible bone sheet according to  claim 14  wherein said cortical cancerous bone sheet is cut from pelvic allograft tissue. 
     
     
       24. A sterile flexible bone sheet according to  claim 14  wherein said cortical cancerous bone sheet is cut from cancaneal allograft tissue. 
     
     
       25. A sterile flexible bone sheet according to  claim 14  wherein said sheet has a width and length ranging from 1–20 cm. 
     
     
       26. A sterile flexible bone sheet for use during the in vivo replacement or reformation of preselected portions of a human bone comprising a continuous unitary sheet of demineralized natural bone with a cortical layer and a cancerous layer with a cortical/cancellous interface, the thickness of said sheet comprising a cortical layer ranging in thickness from 1 mm to 3 mm and a cancellous layer ranging in thickness from 1 mm to 3 mm, the sheet being capable of being bent from its original shape to conform to the configuration of a bone to be repaired without damage to the sheet, said sheet being capable of inducing osteogenesis at the bone region. 
     
     
       27. A sterile flexible bone sheet according to  claim 26  wherein said cortical cancellous bone sheet is cut from tibial allograft tissue. 
     
     
       28. A sterile flexible bone sheet according to  claim 26  wherein said cortical cancellous bone sheet is cut from femoral allograft tissue. 
     
     
       29. A sterile flexible bone sheet according to  claim 26  wherein said cortical cancellous bone sheet is cut from pelvic allograft tissue. 
     
     
       30. A sterile flexible bone sheet according to  claim 26  wherein said cortical cancellous bone sheet is cut from cancaneal allograft tissue. 
     
     
       31. A sterile flexible bone sheet for use during the in vivo replacement or reformation of preselected portions of an animal skeletal system comprising of a continuous unitary sheet of demineralized natural bone with a cortical layer and a cancellous layer with a cortical cancerous interface, said demineralized bone having a residual calcium weight ranging from 3.0% to 8.0% by weight of the demineralized bone mass with the thickness of said sheet ranging from 2.0 mm to 8.0 mm, said sheet containing buffered hyaluronic acid or a derivative of same with a molecular weight over 700,000 Daltons and having a neutral pH, the bone sheet being capable of being bent from its original shape to conform to the configuration of bone to be repaired without damage to the sheet, said sheet being capable of inducing osteogenesis at the bone region. 
     
     
       32. A sterile flexible bone sheet for use during the in vivo replacement or reformation of preselected portions of a human bone comprising a continuous unitary sheet of demineralized natural bone with a cortical layer, a cancerous layer and a cortical cancerous interface said demineralized natural bone having a residual calcium ranging from 3.0% to 8.0% by weight of the demineralized bone mass with the thickness of said sheet ranging from 2.0 mm to 6.0 mm, said sheet containing therein, a hydrogel taken from a group consisting of hyaluronic acid, sodium hyaluronate or derivatives thereof with a molecular weight over 700,000 Daltons and having a neutral pH with an osmolality of 290 mmol/kg to 300 mmol/kg, the sheet being capable of being bent from its original shape to conform to the configuration of a bone to be repaired without damage to the sheet, said sheet being capable of inducing osteogenesis at said bone to be repaired. 
     
     
       33. A method of making a bone sheet with cortical and cancerous portions comprising:
 a). cutting a human bone into substantially tubular portions; 
 b). cleaning marrow, blood and lipids from said tubular cut human bone; 
 c). cutting said cleaned tubular bone longitudinally along its length; 
 d). demineralizing said cut tubular bone rendering the same flexible; and 
 e). pulling the ends of said bone formed by said longitudinal cut apart to form a bone sheet with cortical and cancellous portions. 
 
     
     
       34. A sterile flexible bone sheet according to  claim 33  including the step of adding 1% to 5% hyaluronic acid by weight to the bone sheet. 
     
     
       35. A sterile flexible bone sheet according to  claim 33  wherein said sheet is demineralized to have residual calcium ranging from 3.0% to 8.0% by weight of the demineralized bone mass. 
     
     
       36. A sterile flexible bone sheet according to  claim 33  wherein said demineralized sheet has a neutral pH.